Download or read book The Dynamics of Wind in the Vicinity of Progressive Water Waves written by Omar H. Shemdin and published by . This book was released on 1966 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents a fundamental study of the dynamics of wind in the vicinity of progressive water waves. The normal pressure distribution and the structure of the velocity profile immediately shows progressive water waves are investigated. The theory of Miles (1957) on the generation of surface waves by shear flows predicts a phase shift between the pressure distribution along a wavy surface and the wave itself. This shift becomes responsible for the transfer of energy from air to water due to normal pressure, thereby causing the waves to grow. An experimental verification of this theory is sought. The aerodynamic perturbation-pressure at the air-water interface was measured under two conditions: (1) the pressure sensor following the water surface and (2) the pressure sensor fixed in space above the crest. The results indicate that a pressure shift does exist as predicted by Miles within the assumptions of the theory. Furthermore, the results demonstrate clearly the importance of using a pressure sensor which follows the water surface in obtaining meaningful pressures at the air-water interface. The boundary layer above the water surface was also investigated and the results correlated with the measured pressures. Mean velocity profiles with and without mechanically-generated waves as well as instantaneous velocity profiles above the crest and trough of a mechanically-generated wave were obtained. Contrary to what is normally assumed, the results indicate that there exists a difference in structure between the boundary layer in the vicinity of water waves and that along a flat plate.
Download or read book NBS Special Publication written by and published by . This book was released on 1968 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interaction of Ocean Waves and Wind written by Peter Janssen and published by Cambridge University Press. This book was released on 2004-10-28 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was published in 2004. The Interaction of Ocean Waves and Wind describes in detail the two-way interaction between wind and ocean waves and shows how ocean waves affect weather forecasting on timescales of 5 to 90 days. Winds generate ocean waves, but at the same time airflow is modified due to the loss of energy and momentum to the waves; thus, momentum loss from the atmosphere to the ocean depends on the state of the waves. This volume discusses ocean wave evolution according to the energy balance equation. An extensive overview of nonlinear transfer is given, and as a by-product the role of four-wave interactions in the generation of extreme events, such as freak waves, is discussed. Effects on ocean circulation are described. Coupled ocean-wave, atmosphere modelling gives improved weather and wave forecasts. This volume will interest ocean wave modellers, physicists and applied mathematicians, and engineers interested in shipping and coastal protection.
Download or read book Report written by United States. National Bureau of Standards and published by . This book was released on 1968 with total page 696 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Operational Analysis and Prediction of Ocean Wind Waves written by Madhav L. Khandekar and published by Springer Science & Business Media. This book was released on 2013-03-07 with total page 223 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph is an attempt to compile the present state of knowledge on ocean wave analysis and prediction. The emphasis of the monograph is on the development of ocean wave analysis and predic tion procedures and their utility for real-time operations and appli cations. Most of the material in the monograph is derived from journal articles, research reports and recent conference proceedings; some of the basic material is extracted from standard text books on physical oceanography and wind waves. Ocean wave analysis and prediction is becoming an important activity in the meteorological and oceanographic services of many countries. The present status of ocean wave prediction may be compar able to the status of numerical weather prediction of the mid-sixties and early seventies when a number of weather prediction models were developed for research purposes, many of which were later put into operational use by meteorological services of several countries. The increased emphasis on sea-state analysis and prediction has created a need for a ready reference material on various ocean wave analysis and modelling techniques and their utility. The present monograph is aimed at fulfilling this need. The monograph should prove useful to the ocean wave modelling community as well as to marine forecasters, coastal engineers and offshore technologists. The monograph could also be used for a senior undergraduate (or a first year graduate) level course in ocean wave modelling and marine meteorology.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydraulic Research in the United States 1968 written by United States. National Bureau of Standards and published by . This book was released on 1969 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectral Measurements and Growth Rates of Wind generated Water Waves written by Alex J. Sutherland and published by . This book was released on 1967 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power spectral density measurements were made of the water surface displacement in a wind-generated wave train in the Stanford Wind, Water-wave Facility. Two of the more interesting features of the measured spectra--the presence of a second peak and the lack of an equilibrium range--are fully discussed. Growth rates of different wave components were determined from the measured spectra. The resulting values were compared with those predicted by the viscous Reynolds stress mechanism of energy transfer from wind to wave which was proposed by Miles. Where the growth was exponential the theory could be made to predict growth rates successfully at wave numbers less than 15.0 ft( -1). At higher wave numbers the theory predicted values an order of magnitude larger than those measured in the Stanford facility. Limited regions of linear growth were found at the lowest wind speed for low frequency components. The scatter in the data did not permit a quantitative comparison with theory to be made for this range. (Author).
Download or read book Shore Protection Manual written by Coastal Engineering Research Center (U.S.) and published by . This book was released on 1977 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Current Hydraulic Laboratory Research in the United States written by and published by . This book was released on 1968 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Naval Research Reviews written by and published by . This book was released on 1968 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shore Protection Manual Chapters 1 4 written by and published by . This book was released on 1975 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Analytical Investigation of the Air Velocity Profile Above Progressive Waves written by Omar H. Shemdin and published by . This book was released on 1967 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of propagating waves on the mean velocity profile is sought especially. Both the instantaneous and mean velocity profiles were obtained with the use of high response total head and static pressure probes, in conjunction with a wave height gage. Experimental evidence is presented which suggests that the air velocity responds to the wave motion at the air-water interface. The dependence of the mean velocity profile on wave frequency is investigated over mechanically-generated waves having a constant amplitude. Also the dependence of the mean velocity profile on wave amplitude is investigated over mechanically-generated waves with a specified frequency. The results are viewed in light of a theoretically constructed velocity profile which incorporates the effect of wave-induced motion. The theoretical results suggest that the measured mean velocity profile is influenced by the wave motion in a vicinity of approximately three wave amplitudes above the mean water surface. The results also suggest that the wave influence is twofold. The first is due to the fact that a velocity measuring instrument continuously shifts streamlines when measuring the air velocity above a perturbed water surface. The second is due to the wave-induced perturbation in the air velocity. (Author).
Download or read book Response of Gravity Water Waves to Wind Excitation written by James B. Bole and published by . This book was released on 1967 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary purpose of this work was to study the response of gravity water waves to wind excitation, and in particular the applicability of the Miles inviscid shear-flow theory of gravity wave growth, by conducting experiments in a laboratory wind-wave channel under conditions approximating the assumptions of the mathematical model. The secondary objective was to document features of the coupled wave-response/wind-excitation system for comparison with the assumptions of Miles' theory. Mechanically generated wave profiles were measured with capacitance wire sensors and wave energy was calculated at seven stations spaced at 10-ft intervals along the channel test section. Waves varied in length from about 2.5 to 6.5 ft and maximum wind speeds ranged from 12 to 44 fps. Two sources of evidence indicate that without some modification the Miles inviscid theory may be inapplicable to gravity wave growth on a sufficiently rough water surface. First, the measured growth rates were significantly larger than theory predicts. Second, the superposed ripple standard deviations were larger than the respective critical layer thicknesses. Measured energy growth is not inconsistent with the energy transfer expected from flow separation. (Author).
Download or read book Offshore Petroleum Engineering written by Marjorie Chryssostomidis and published by Burns & Oates. This book was released on 1978 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of the Urban Planning and Development Division written by American Society of Civil Engineers. Urban Planning and Development Division and published by . This book was released on 1970 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:
